This invention generally relates to a fuel delivery system and method for an energy conversion device. More particularly, this invention relates to a method for conditioning a fuel-air mixture to improve combustion.
Energy conversion devices such as for example, a gas turbine engine transform energy within fuel to produce useful work. Fuel is mixed with air and ignited within a combustion chamber to release this energy, for example by creating a flow of exhaust gases in a gas turbine engine. The fuel typically includes an amount of dissolved oxygen. The dissolved oxygen within the fuel causes autooxidative reactions to occur at elevated fuel temperatures. The autooxidative reactions produce insoluble products commonly referred to as “coke” or “coking”. This “coking” is not desirable as it can clog and disrupt fuel flow and thereby limits the temperature at which fuel may be heated.
Conventional gas turbine engines utilize liquid fuel as a cooling medium to remove heat from other systems. Reducing dissolved oxygen from the liquid fuel increases the temperature threshold at which autooxidative reactions reach a certain reaction rate, thereby increasing the thermal capacity for removing heat to the liquid fuel. Removal of oxygen from fuel to increase the thermal capacity of the fuel to provide an increased capacity for removing heat from other systems.
Fuel is combined with air in a combustor of the typical gas turbine engine, or in other types of combustion chambers for other known energy conversion devices. Fuel entering the combustor is typically in a liquid phase. The fuel vaporizes due to heat in the combustor and then reacts with the oxidizer. However, fuel in vapor phase burns more readily than the liquid fuel because it has already been vaporized and is typical of higher temperature than liquid fuel due to evaporation. However, fuel is not typically heated to a temperature that will vaporize a portion of the liquid fuel before entering the combustor due to the limitations on fuel temperature to avoid undesirable coking.
Accordingly, it is desirable to design and develop a system and method for vaporizing fuel prior to entering the combustor and introducing the vaporized fuel into the combustor in a proper manner to improve flame stabilization and burn efficiency within a combustor.